In recent years, semiconductor devices in which a resin structure is provided on a semiconductor element by using a semiconductor process have increased. For example, an MLA (microlens array) and a DOE (diffraction optical element) are known in which a lens is formed on an image sensor such as a CCD or a CMOS in an integral manner.
In particular, plural MLAs or DOEs are used frequently for complex processing for increase in focusing efficiency, color difference correction, or the like. For employing plural MLAs or DOEs, the alignment accuracy and its adjustment during manufacture are important.
Patent Document 1 entitled “Diffraction Optical Element and Optical System Using It” discloses a method for improving the wavelength dependency of the diffraction efficiency using diffraction optical elements that are accumulated in two or more stacked layers on a substrate. In this document, a technique is introduced in which the edges of each diffraction grating can be caused to assume obtuse angles by chamfering the edge portion of each grating portion, whereby the processability of a grating shape at the time of cutting or the like and the shape transferability at the time of molding of edge portions are increased. Patent Document 1: Japanese Unexamined Patent Application Publication No. H11-223717